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| - | ====== EVO: Engine Mechanicals - Sub-04A ====== | + | ====== EVO: Engine Mechanicals - Sub-04C ====== |
| ====== Installing the Rocker Boxes ====== | ====== Installing the Rocker Boxes ====== | ||
| - | See also [[techtalk: | + | See also in the Sportsterpedia; |
| + | * [[techtalk: | ||
| + | * [[techtalk: | ||
| + | \\ | ||
| + | One issue in installing the rocker box is that it has no alignment method. ((aswracing of the XLFORUM https:// | ||
| + | Basically, every time you put it on, it's in a different place. \\ | ||
| + | When installing the rocker boxes, be sure to put them on with the engine positioned such that the cams aren't trying to open the valves. ((aswracing of the XLFORUM https:// | ||
| + | Else you can damage parts. \\ | ||
| + | ===== Compatibility ===== | ||
| + | Middle rocker box: \\ | ||
| + | The 86-90 doesn' | ||
| + | So due to functionality, | ||
| + | But the 91-03 middle cover will fit 86-90 boxes. \\ | ||
| + | |||
| + | ===== Gaskets ===== | ||
| + | Clean the mating surfaces of all oil / trash before setting the gaskets in place. \\ | ||
| + | With the bolts ' | ||
| + | It's easy to 'just nudge' the top section and squeeze a portion of the rubber gasket out while positioning it. \\ | ||
| + | See [[http:// | ||
| + | |||
| + | {{: | ||
| + | |||
| + | ===== Bolt Installation Sequence ===== | ||
| + | The FSM details the proper installation sequence of the bolts. \\ | ||
| + | Installing the bolts in the proper order prevents potentially warpage of the cover(s). \\ | ||
| + | It also mentions making sure that both valves are closed prior to removal. \\ | ||
| + | |||
| + | On assembly, it's even more important to slowly tighten things in the proper order to allow the lifters to bleed down. \\ | ||
| + | (prevents things like bent push rods and destroying the cam bushings). \\ | ||
| + | Also, make sure you can spin the push rods BEFORE turning the motor over the first time. \\ | ||
| + | Obviously, you can skip these steps and get lucky. \\ | ||
| + | But, why? Just follow the manual, it's easy enough to do correctly. \\ | ||
| + | |||
| + | Below are pictures of the lower rocker box. \\ | ||
| + | The circled areas are where the bolts would be: \\ | ||
| + | |||
| + | **On assembly**: ((Screw Loose Dan of the XLFORUM https:// | ||
| + | |||
| + | * Work in this order. Blue-> | ||
| + | * An easy way to remember the order is to work from the larger bolts to the smaller ones. | ||
| + | * If you start with the red ones, you can easily strip the threads in the heads. | ||
| + | |||
| + | **Torque values**: \\ | ||
| + | Installing the bolts in the correct order doesn' | ||
| + | While many experienced guys won't use a torque wrench on the smaller fasteners, it is suggested to use one. \\ | ||
| + | It doesn' | ||
| + | |||
| + | * Blue - 18-22 ft-lbs | ||
| + | * Red - 135-155 in-lbs | ||
| + | * Yellow - 135-155 in-lbs | ||
| + | |||
| + | |91-03 style lower rocker box ((photo by Hippysmack))|04 and up style lower rocker box ((photo by Screw Loose Dan of the XLFORUM https:// | ||
| + | |{{: | ||
| + | |||
| + | ===== Check Pushrod Length ===== | ||
| + | A hydraulic lifter has a plunger in it's body that has about .200" of movement. ((http:// | ||
| + | In the ideal world, the plunger is approximately centered in it's travel, meaning it's preloaded about .100". \\ | ||
| + | So in theory,\\ | ||
| + | It could move up, thus lengthening the effective length of the lifter to compensate for a pushrod that's up to .100" too short. \\ | ||
| + | And likewise, it could move down, thus shortening the effective length of the lifter to compensate for a pushrod that's up to .100" too long. \\ | ||
| + | This self adjusting action is also useful for compensating for changes in needed pushrod length due to engine temp variations. \\ | ||
| + | As the motor heats up, the top end grows and the lifter automatically takes up the slack. \\ | ||
| + | In reality, \\ | ||
| + | The useful operating range of the lifter plunger is only about .050" in either direction away from centered (.050" to .150" of preload). \\ | ||
| + | Outside of this range, the self adjusting function doesn' | ||
| + | |||
| + | You can measure lifter pre-load to determine if the pushrods are in the size range needed. This method will get you close. ((http:// | ||
| + | The cam lobes should be down (as they should be when installing a rocker box). \\ | ||
| + | Set the pushrods in place (the longer one goes on the exhaust) and then place the gasket and rocker box on top installing the four big screws only. \\ | ||
| + | Finger tighten the left (spark plug) side, while making sure the right side is resting with the upper pushrod ends sitting in the cups on the rocker arms. \\ | ||
| + | Use a caliper to measure how much gap you have between the rocker box and the rocker box gasket. \\ | ||
| + | The lifter preload should be app. .100" but anywhere between .050" and .150" should work. \\ | ||
| + | Aftermarket pushrods can be purchased in longer or shorter lengths than stock ones to get the measurement within .100". | ||
| + | |||
| + | {{: | ||
| \\ | \\ | ||
